Asphalt composition

Abstract

The present invention relates to an asphalt composition having excellent durability after being dried, an asphalt mixture, and a method for producing an asphalt mixture.Disclosed are [1] an asphalt composition containing asphalt, a thermoplastic elastomer, and a polyester, wherein the polyester has a softening point of 90° C. or higher and 140° C. or lower and a glass transition point of 40° C. or higher and 80° C. or lower, and a ratio of the polyester is 1 part by mass or more and 17 parts by mass or less based on 100 parts by mass of the asphalt; [2] an asphalt mixture including the asphalt composition as set forth [1] and an aggregate; and [3] a method for producing an asphalt mixture, including a step of mixing a heated aggregate, asphalt, a thermoplastic elastomer, and a polyester, wherein the polyester has a softening point of 90° C. or higher and 140° C. or lower and a glass transition point of 40° C. or higher and 80° C. or lower, and a ratio of the polyester is 1 part by mass or more and 17 parts by mass or less based on 100 parts by mass of the asphalt.

The invention claimed is: 
     
       1. An asphalt composition comprising asphalt, a thermoplastic elastomer, and a polyester, wherein
 the polyester has a softening point of 90° C. or higher and 140° C. or lower and a glass transition point of 40° C. or higher and 80° C. or lower, and 
 a ratio of the polyester is 1 part by mass or more and 17 parts by mass or less based on 100 parts by mass of the asphalt. 
 
     
     
       2. The asphalt composition according to  claim 1 , wherein the polyester comprises an alcohol component-derived structural unit containing 60 mol % or more of an alkylene oxide adduct of bisphenol A and a carboxylic acid component-derived structural unit. 
     
     
       3. The asphalt composition according to  claim 2 , wherein the polyester comprises 50 mol % or more of an aromatic dicarboxylic acid compound based on the carboxylic acid component. 
     
     
       4. The asphalt composition according to  claim 2 , wherein the polyester comprises 50 mol % or more of an aliphatic dicarboxylic acid compound based on the carboxylic acid component. 
     
     
       5. The asphalt composition according to  claim 1 , wherein the polyester has a hydroxyl value of 1 mgKOH/g or more and 70 mgKOH/g or less. 
     
     
       6. The asphalt composition according to  claim 1 , wherein the thermoplastic elastomer is at least one selected from the group consisting of a styrene/butadiene block copolymer, a styrene/butadiene/styrene block copolymer, a styrene/butadiene random copolymer, a styrene/isoprene block copolymer, a styrene/isoprene/styrene block copolymer, a styrene/isoprene random copolymer, an ethylene/vinyl acetate copolymer, and an ethylene/acrylic acid ester copolymer. 
     
     
       7. The asphalt composition according to  claim 1 , wherein the thermoplastic elastomer is at least one selected from the group consisting of a styrene/butadiene block copolymer, a styrene/butadiene/styrene block copolymer, a styrene/butadiene random copolymer, a styrene/isoprene block copolymer, a styrene/isoprene/styrene block copolymer, and a styrene/isoprene random copolymer. 
     
     
       8. An asphalt mixture comprising the asphalt composition according to  claim 1  and an aggregate. 
     
     
       9. A method for producing an asphalt mixture, comprising a step of mixing a heated aggregate, asphalt, a thermoplastic elastomer, and a polyester, wherein
 the polyester has a softening point of 90° C. or higher and 140° C. or lower and a glass transition point of 40° C. or higher and 80° C. or lower, and 
 a ratio of the polyester is 1 part by mass or more and 17 parts by mass or less based on 100 parts by mass of the asphalt. 
 
     
     
       10. The method for producing an asphalt mixture according to  claim 9 , wherein in the mixing step,
 (i) the asphalt and the thermoplastic elastomer are added to and mixed with the heated aggregate, and then, the polyester is added and mixed; or 
 (ii) the asphalt, the thermoplastic elastomer, and the polyester are simultaneously added to and mixed with the heated aggregate.